Stock-Based Compensation, Phantom Stock Option Plan and Long-term Incentive Plan (Details) - 2011 Phantom Stock Option and Long-term Incentive Plan [Member] - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Jun. 30, 2019
Stock option activity, shares [Roll Forward]
Outstanding at beginning of year (in shares)	1,711,600	1,634,160
Options granted (in shares)	614,700	592,700
Options forfeited (in shares)	(7,000)	0
Options paid in cash (in shares)	0	(484,760)
Outstanding at period end (in shares)	2,319,300	1,742,100
Stock option related information [Abstract]
Cash paid out on options vested	$ 0	$ 1,704
Compensation expense recognized	645	$ 516
Total liability for the Plan	$ 4,800		$ 4,100